Blow out closure construction



April 22, 1969 R. H; ET MORE 3,440,022

BLOW OUT OLOsuRE CONSTRUCTION Filed March 15, 1966 sheet l of 2 F/G. 6 30 'O2 '2 F/G. 4 Emy/2% los |02 |08 38 Afro/MEX April 22, 1969 R. H. ELMORE BLOW OUT CLOSURE CONSTWJC'IIOJ Filed March l5, 1966 INVENTOR. RUSH H. ELMORE ATTORNEY United States Patent O Int. Cl. B011 1/00 U.S. Cl. 23-292 10 Claims ABSTRACT F THE DISCLOSURE A closure construction for a fume hood including closure members that are mounted on the fume hood to pivot and swing out of closing relation with the fume hood entrance when an excessive pressure occurs in the fume hood.

This invention relates to a closure construction for a fume hood and, more particularly, pertains to a closure construction wherein the closure members are adapted to pivot relative to a fume hood in response to explosive forces spontaneously generated in the fume hood thereby to prevent harm to adjacent personnel and property.

Fume hoods are normally utilized in laboratory work to contain and exhaust odious, poisonous and/or corrosive fumes in addition to providing'a means for removing the heat generated by chemical reactions and the like. The fume hood conventionally comprises a confined area which has a front opening or entrance to provide access to the work being performed. The opening is adapted to be closed by closure members such as Safety sashes or doors which are constrained to slide in ap propriately positioned tracks. However, a serious problem arises in the use of such fume hoods when the reaction undergoing experimentation is or is likely to become explosive in nature. The forces produced by such explosions usually shatter the closure members thereby causing damage to personnel and property in the vicinity of the fume hood.

Accordingly, a desideratum of the Ipresent invention is to provide a closure construction for fume hoods which utilizes closure members which are adapted to absorb some of the explosive forces generated therein.

Another object of the present invention is to provide a closure construction of the type disclosed which is compatible for use in existing fume hoods.

Still another object and feature of the present invention resides in the novel details of construction which provide a closure construction for a fume hood which allows the closure members, in one of their positions, to pivot outward relative to the fume hood in response to an explosion within the fume hood and, which in another of their positions, prevents the pivoting the closure members when they are in overlapping relation to each other, as -when personnel are working with the fume hood, to prevent injury to such personnel.

Other and further objects of this invention reside in the structures and arrangements hereinafter more fully described with reference to the accompanying drawings in which:

FIG. l is a perspective view of a fume hood utilizing a closure construction made in accordance with the present invention,

FIG. 2 is a top plan view of the sashes shown in FIG. 1, illustrating their relative staggered positions when they completely close the opening in the fume hood,

FIG. 3 is a top plan view of the closure members similar to FIG. 2, showing two of the closure members positioned one in front of the other to provide access to the interior of the fume hood,

3,440,022 Patented Apr. 22, 1969 ICC FIG. 4 is a sectional Iview of the closure members taken along line 4-4 of FIG. 3, with parts broken away and to an enlarged scale,

FIG. 5 is a rear elevational view of a closure member shown in FIG. 4.

FIG. 6 is a top plan view of the closure members similar to FIG. 3, illustrating the closure members partially pivoted outward and interlocked,

FIG. 7 is a side elevational view of the closure members shown in FIG. 6, with parts broken away and to an enlarged scale, and

FIG. 8 is a side elevational view of at least two of the staggered closure members of FIG. 2 pivoted outward.

In the description of the present closure construction which follows, reference is made to a sash or door construction for so-called bench type fume hoods. However, the Iprinciples of the present invention are equally applicable to a fume hood of the step-in type wherein larger sashes or doors are utilized to close the opening of the fume hood. Accordingly, the present invention is not to be interpreted as being limited to an specific type of fume hood, but may find utility in fume hoods in general.

A fume hood which advantageously may be provided with a closure construction according to the present invention is illustrated in FIG. 1 and is designated generally by the numeral 10. The fume hood 10 is of conventional construction and comprises the top fall 12, a bottom wall 14, opposed side walls 16 and 18, a rear -wall 20 and a front wall 22. The front wall 22 is provided with an opening or entrance 24. The entrance 24 is adapted to be closed by four safety sashes designated by the numerals 28, 30, 32 and 34. In practice, the sashes 28-34 are substantially equal in size. The sashes are connected to the fume hood 10 so that the sashes 30 and 32 may be placed in face-to-face position with respect to each other and each respectively with their adjacent sashes 28 and 34, as described in detail below. This limits the maximum extent that the fume hood can be opened to onehalf the total width of the entrance 24.

Received within the fume hood 10 may be a blower (not shown) which exhausts the fumes out of the fume hood through a duct system 26, which disperses the fumes into the atmosphere at a point remote from the room in which the fume 10 is located. Normally, in fume hoods of the type described, the sashes are provided with glass so that the operator may observe the reactions that are occurring within the fume hood proper. However, in those cases where a spontaneous explosion has occurred within the fume hood, the explosive forces ha-ve caused the glass to shatter, thereby causing harm to personnel and property located in the vicinity of the fume hood or to the fume hood itself.

In order to obviate the abovementioned hazardous disadvantages, the closure construction of the present invention includes a longitudinally extending upper guide member 36 and a lower guide member 38 which are connected to the respective upper and lower edges of the entrance 24 in the front wall 22 of the fume hood 10 (FIG. 4). The upper guide member 36 includes a front track 40 and a co-extensive rear track 42 which are provided with respective bottom walls 44 and 46. Provided on the bottom wall 44 and integral therewith are depending anges 50 which define a central slot 48 therebetween. Similarly, provided on the bottom wall 46 of the track 42 are depending flanges 52 which define a central slot 54 therebetween. The respective tracks 40 and 42 are adapted to receive sash support members 58 to pivotally and slidably connect the respective sashes 28-34 to the fume hood 10.

The support members 58 are identical in construction and one of the support members is shown in detail in FIGS. 4 and 5. It is to be noted that two such support members 58 support each one of the sashes. For example, one support member 58 is connected to the sash 30 (FIG. 5) adjacent to the left hand edge of the sash and another support member 58 is connected to the sash 30 adjacent to the right-hand end of the sash. More particularly, the support members 58 associated with the sash 30, include a block 60 which is received in the slot 48 and which extends above the bottom wall 44 of the track 40. The block 60 is spaced from the flanges S0 so that the block is slidable within the slot 48.

A shaft 62 is iixably received through one end of the block 60 and mounts a roller 64. Another shaft 66 is xedly received through the block 60 adjacent to the other end of the block and mounts a roller 68. Threadedly received within the block 60 is a depending threaded Vshaft 70 which threadedly engages one end of a hinge 72. Depending from the other end of the hinge 72 and threadedly engaged therewith is a threaded shaft 74 which extends through a top rail 76 of the sash 30 and which receives a nut 78 on the end thereof to connect the sash 30 with the support member 58. Accordingly, the sash 30 may beadjusted with respect to the upper and lower guide members 36 and 38 by rotating the threaded shafts 70 and 74. That is, when the shaft 70 and/or the shaft 74 is rotated in one direction, the sashes may be raised in the opening 24 whereas when the shaft 70 and/or the shaft 74 is rotated in the opposite direction, the sash will be lowered in the opening 24.

It will now be obvious that the support members S8 shown in FIG. 5 pivotably and slidably mount the sash 30 on the fume hood 10. In particular, the rollers 64 and 68 are adapted to engage and roll along the bottom wall 44 of the track 40 on each side of the slot 48 thereby connecting the sash 30 with the fume hood 10 for slidable movement in the entrance 24. On the other hand, the hinge 72 provides a pivotal connection for the sash 30 which allows the sash 30 to pivot outwardly from the fume hood 10. The sash 34 is connected to the front track 40 in a manner similar to the connection described above and the sashes 28 and 32 are connected to the rear track 42 in a like manner.

Since the sashes 28-34 are similar in construction, only the sash 30 will be described in detail, it being understood that the remaining sashes embody the same novel details and concepts of the present invention. Accordingly, the sash 30, as shown in FIG. 5, comprises an upper rail 76 (noted above), a lower rail 80 and respective side stiles 82 and 84. Extending rearwardly on the top rail 76 and the bottom rail 80 are mounts 86 which are spaced above the respective edges of the top and bottom rails. A safety glass 88 which is provided with a rubber channel 90 about its outer edges, is received against the mounts 86. Glass retaining clamps 92 are positioned on the rear surface of the rubber channel 90 and they are connected to the respective mounts 86 by the screws 94 thereby to clamp the glass 88 between the clamps 92 and the respective upper and lower portions of the respective top rail 76 and the bottom rail 80.

A feature of the present invention resides in the provision of interlock means which are connected to the respective sashes and which are releasably retained in the lower guide member 38. The interlock means maintains the respective sashes in a vertical or closing position wherein the sashes are adapted to close portions of the entrance 24. However, the interlock means are adapted to allow the sashes to pivot outwardly, under the conditions described in detail below, thereby to open the entrance 24. Additionally, the interlock means are further adapted to prevent the pivoting of the sashes to the open position when a sash connected to the front track 40 is in overlapping or face-to-face relation with a sash connected to the rear track 42, as when personnel are working at the hood. This prevents the sashes from pivoting or ying out and harming such personnel- More particularly, the interlock means includes hangers 96 which are connected to the respective side stiles 82 and 84 and to which are pivotally connected depending guide rods 98 by means of pivot pins 100 which extend through appropriate apertures in the guide rods 98 and the hangers 96. The guide rods 98 extend beyond the lower rail 'and terminate in guide blocks 102 which are respectively received in the guide member 38. Provided in the rail 80 are slots 99 which allow the rods 98 to pivot rearwardly of the sash 30. Open-ended snap clips 104 are mounted on the stiles 82 and 84 below the hangers 96 and releasably receive the guide rods 98 therein to releasably retain the guide rods in a vertical position. It will now be obvious that the guide rods 98 may pivot rearwardly with respect to the sash 30 about the pivot pins 100 when the sash 30 pivots outwardly with respect to the fume hood 10 about the hinge 72.

The lower guide member 38 comprises open topped front and rear channels 106 and 108 which underlie the respective front and rear tracks 40 and 42. Connected to the top front edge of the channel 106 is an air foil 110 that extends forward and then tapers downwardly and outwardly. The guide blocks 102 associated with the sashes connected to the front track 40 are received in the front channel 106 whereas the guide blocks 102 associated with the sashes connected to the rear track 42 are received in the channel 108. For example, as shown in FIG. 4, the guide blocks 102 associated with the sash 30 are received in the channel 106 and the guide blocks 102 associated with the sash 32 are received in the channel 108. lt is to be noted that the guide blocks 102 are greater in width than the respective sashes 28-34 for reasons which will become apparent from a consideration of the operation of the invention as described hereinbelow.

In operation, when it is desired to completely close the entrance 24, the sashes 28-34 are slid along the respective tracks 40 and 42 so that the sashes will be staggered with respect to one another, as shown in FIG. 2 wherein each sash is adapted to close a different but adjacent portion of the entrance 24. While FIG. 2 illustrates one arrangement of the sashes, it is to be noted that any one sash may be interchanged in position with another sash (i.e., the positions of the sashes 34 and 32 may be interchanged or the positions of the sashes 30 and 34 may be interchanged) it being necessary only that the sashes be staggered with respect to each other to close the entrance 24. For this arrangement of the sashes, the sashes 28-34 will be oriented in the vertical or closing position with each of the guide rods 98 being received in a respective snap clip 104 and with each of the guide blocks 102 being received in its associated channel comprising the lower guide member 38.

If an explosion occurs Within the fume hood 10 when the sashes are in their staggered completely closing position of FIG. 2, the explosive force will be substantially equally distributed against the rear surfaces of each of the sashes thereby tending to push the sashes outwardly. Hence, the sashes 28-34 will pivot simultaneously outwardly about the hinges 72 to open the entrance 24 and allow the explosive forces to be dissipiated into the room in which the fume hood 10I is located, thereby preventing the shattering of the respective sashes.

For example, as the sash 30 pivots outwardly from the fume hood 10 about the hinge 72 to its guide blocks 102 will engage the front wall of the channel 106 and will be prevented from moving with and at the same speed as the sash 30. However, continued outward movement of the sash 30 will cause the guide rods 98 to move out of the restraining snap clips l104 and pivot rearwardly with respect to the sash 30 to about the pivot pins 100. The rods `98 will move rearwardly with respect to the sash 30 until the sash 30 has moved outwardly and upwardly a distance such that the guide blocks 102 clear the front wall of the channel 106.

Similar movements will occur with respect to the sashes 28, 32 and 34. After the explosive forces have been dissipated, the sashes 28-34 will tend to fall and pivot back to their vertical or closing position under the influence of gravitational forces. However, the guide blocks '102, which normally extend below the respective sashes, will engage the air foil .110 (as shown in FIG. 8) to prevent the sashes from entering the fume hood on the back or return swing to further damage the apparatus therein.

As noted hereinabove, a feature of the present invention resides in the interlock means which prevents the pivoting of the sashes to their open position when personnel are actually Working at the fume hood It is to be noted that when an operator is working at the fume hood, two sashes such as 30 and 32 (FIG. 3) generally are moved to overlapping or face-to-face positions wherein the sash 30 is located in front of the sash 32. The operator then stands in front of the overlapping sashes 30 and 32 and extends his hands through the opening between these sashes and respective sashes 28 and 34 thereby to handle and manipulate the various retorts, curcibles and like articles within the fume hood 10.

If an explosion occurred at that time and if no safety features were provided, the sashes 30 and 32 would pivot about the hinges 72 and y into the face of the operator. However, this action is prevented in the present invention. Accordingly, if an explosion occurs when the sashes 30 and 32 are positioned as shown in IFIG. 3, the explosive force will be applied initially to the rear face of the sash 32 thereby causing the sash 32 to pivot outwardly first. As the sash 32 pivots outwardly, the guide blocks |102 associated therewith move into engagement with the front wall of the chanel 108 to cause the rods 98 connected to the sash 32 to pivot rearwardly with respect thereto. As seen in FIG. 7, as the sash 32 pivots outwardly it overlies the top surface of the guide blocks 102 associated with the sash 30. The force applied to the rear surface of the sash 32 is then transmitted to the front sash 30 through the sash 32. The sash 30 will then proceed to pivot outwardly and about the hinges 72 as described hereinabove. However, as the sash 30 begins to move outwardly, the guide blocks 102 associated therewith engage both the front wall of the channel 106 and lock beneath the bottom surface of the sash 32 and accordingly, they will be constrained within the channel 106.

Since the guide block 102 is rigidly connected to the sash 30 by means of the rod 9-8, the sash 30 will be prevented from further outward movement. Moreover, the sash 32 likewise will be blocked from further outward movement by the sash 30. Accordingly, the sashes 30 and 32 will remainin the closed position. Thus, the forces due to the explosion will be dissipated through the openings provided in the fume hood 10 between the overlapping sashes 30 and 32 and the remaining sashes 28 and 34.

If the explosive force was great enough, the sashes 38 and 34 would similarly pivot about their hinges 72, in the manner noted above, to further provide space through whichthe explosive forces can be dissipated. Furthermore, it is to be noted that the sashes do not necessarily have to be completely in overlapping position with respect to each other in order to prevent a sash from iiying outwardly due to explosive forces within the frame hood. That is, it is suicient for one of the rear sashes 28, 32 to overlie at least one of the guide blocks 102 of one of the front sashes 30 or -34 to prevent that particular front sash from moving upwardly and outwardly to cause harm to personnel.

Accordingly, a sash construction for a fume hood has been provided which is adapted to pivot with respect to the fume hood in response to explosive forces within the fume hood to allow such explosive forces to be dissipated without harming personnel or property in the vicinity of the fume hood. Additionally, safety means are provided to prevent such sashes from contacting personnel who are working at the fume hood at the time of such explosion.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art, without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.

I claim:

1. A closure construction for a fume hood having an entrance in one wall thereof comprising at least one closure member for closing the fume hood entrance,

lirst means connecting said one closure member with the fume hood for sliding movement with respect to the entrance and for pivotal movement between a closing position wherein said one closure member is located within the fume hood entrance to close the entrance and an open position wherein said closure member is located outside the fume hood entrance to open the entrance,

and second means connected with said one closure member and the fume hood for maintaining said closure member in said closed position and for sliding movement with respect to the entrance.

2. A closure construction according to claim 1, in which said first means includes an upper guide member,

and connecting means connecting said one closure member with said upper guide member for pivotal and slidable movement with respect thereto.

3. A closure construction as in claim 2,

in which said connecting means comprises a block mounting a pair of rollers,

said pair of rollers being in rolling engagement with said upper guide means,

hinge means,

and means for connecting said hinge means intermediate said one closure member and said block to provide for the pivotal movement of said one closure member relative to said entrance.

4. A closure construction according to claim 1,

in which said second means includes a lower guide member adapted to be connected to the bottom edge of the entrance,

and interlock means connected to said closure member and releasably received in said lower guide member to releasably retain said one closure member in said closed position.

5. A closure construction for a fume hood as in claim 4,

in which said lower guide member includes a channel having an open top,

said interlock means comprising a rod pivotably connected to said one closure member,

and a guide block connected to the end of said rod and received through the open top of said channel,

whereby pivoting of said one closure member toward the open position causes pivoting of said rod relative to said one closure member to lift said guide block out of said channel to provide for the further movement of said one closure member to the open position.

6. A closure construction or a fume lhood according to claim 1,

wherein said one closure member closes a iirst portion of the entrance of said fume hood,

a second closure member for closing a second portion of the entrance,

third means connecting said second closure member with said fume hood for pivotal movement between a closing position wherein said second closure member is located within the contines of the fume hood entrance to close the second portion of the fume hood entrance and an open position wherein said second closure member is located outside of the fume hood entrance to open the fume hood entrance,

and fourth means connected to said second closure member and releasably connected to the fume hood for maintaining said second closure member in said closed position,

and means on said second closure member adapted to engage said second means on said one closure member when said second closure member begins to move toward said open position to prevent release of said second means from the fume hood, whereby said one closure member and said second closure member are maintained in the closed position.

7. A closure construction according to claim 6,

in which Said -irst means includes a top front track,

and connecting means for connecting said one closure member with said front track for pivotal and slidable movement with respect thereto,

said third means including a top rear track co-extensive with said front track,

and means for connecting said top rear track with said second closure member for pivotal and slidable movement with respect thereto.

8. A closure construction for a fume hood as in claim 6,

in which said second means includes an open-topped front channel connected to the bottom of the entrance,

and interlock means connected to said one closure member and releasably received in said front channel;

said fourth means including a rear channel co-extensive with said front channel,

and lock means pivotally connected to said second closure member and releasably received in said rear channel, whereby said one closure member and said second closure member may be positioned in overlapping relationship with each other,

said means for engaging said second means comprising the lower edge of said second closure member when said one closure member and said second closure member are in an overlapping position.

9. In a fume hood having an opening,

a first door slidable on said fume hood to close and open a respective portion of the opening,

guide means along a defining wall of the opening,

channel means along a defining wall of said opening opposite said guide means,

means on said rst door cooperable with said guide means to guide the first door for sliding movement to close and open the respective portion of the opening and being operable to enable said first door to swing out of the opening, and interlock means on said first door cooperable with said channel means during the sliding of said first door to retain the first door in the opening and operable to move out of cooperation -with said channel means when a force is applied to said first door to enable said first door to swing out of the opening.

10. In a fume hood as in claim 9,

a second door slidable on said fume hood to close and open a second portion of the opening and being adapted to be moved into overlapping relation with said first door, mounting means on said second door cooperable with said guide means to guide said second door for sliding movement to close and open the seco-nd portion of the opening and being operable to enable said second door to swing out of the opening,

and interlock means on said second door cooperable with said channel means during the sliding of said second door to retain the second door in the opening and operable to move out of cooperation with said channel means when a force is applied to said second door to enable said second door to swing out of the opening,

the interlock means on said first door lockingly engaging with said second door when the -force is applied and said rst and second doors are in overlapping relationship.

References Cited UNITED STATES PATENTS 6/1936 Norton et al. l/l934 Feltham.

JAMES H. TAYMAN, Primary Examiner. 

